Welcome to the Chair of Systems Design
At the Chair of Systems Design, ETH Zurich, we perform interdisciplinary Complex Systems Research with a particular focus on the understanding and modeling of phenomena present in social, socio-technical and socio-economic systems. To do so we apply and develop quantitative methods from statistical physics, applied mathematics, computer science and beyond.
You do good scientific work but nobody cites you? Maybe this is because you are not well enough embedded in the scientific social network. In our new paper Predicting Scientific Success Based on Coauthorship Networks (arXiv:1402.7268) we take a look at the question what role mechanisms of social influence play for scientific success. Precisely, we quantify to what extent metrics of centrality of authors in the coauthorship network correlate with citation numbers of their papers. Surprisingly, we find that a machine learning classifier is able to predict whether a paper will be successful or not with a precision of 60 % (and a recall of 18%), based solely on metrics of social network centrality of its authors. This result clearly challenges the perception of "citations" as objective measures of scientific quality.
The recent crisis has brought to the fore a crucial question that remains still open: what would be the optimal architecture of financial systems? We investigate the stability of several benchmark topologies in a simple default cascading dynamics in bank networks. We analyze the interplay of several crucial drivers, i.e., network topology, banks' capital ratios, market illiquidity, and random vs targeted shocks. We find that, in general, topology matters only – but substantially – when the market is illiquid. No single topology is always superior to others. In particular, scale-free networks can be both more robust and more fragile than homogeneous architectures. This finding has important policy implications. We also apply our methodology to a comprehensive dataset of an interbank market from 1999 to 2011.
The latest results of a 5-year collaboration between our group and conservation biologists at the University of Greifswald have been published in Naturwissenschaften. In this new study, we show that a wild colony of bats can flexibly adapt its social structure in response to a dramatic population decline.
Our new paper is out now in PLOS ONE. In a collaboration with microbiologists from the University of Zurich, we have developed a graph layout method to ease the analysis of clustering patterns in the phenotypic profiles of bacteria, here applied to samples from the well-know Aletsch glacier in the Swiss Alps.
How do Research and Development networks evolve over time? Are there any universal patterns or their evolution is industry dependent? Is this evolution time dependent? Can we identify cyclic behavior or there is a monotonic trend? Find out more in our recent paper "The Rise and Fall of R&D Networks" which is now available on arXiv.
The book "Collective Emotions: Perspectives from Psychology, Philosophy, and Sociology" edited by Christian von Scheve, Mikko Salmella is published by Oxford University Press. Chapter 26 "Modeling collective emotions in online social systems" by D.Garcia, A.Garas, and F.Schweitzer gives a nice overview of our research in this area.
Our recent work on the automatic re-modularization of software has been accepted to the International Conference on Modularity 2014. We use a stochastic strategy based on move refactoring and show that the worse the modularity of a given architecture, the better the improvement achieved by our approach.
Together with evolutionary biologists at the University of Zurich, we have published a new manuscript on an information-theoretic approach to coupling and leadership in animal groups. In this arXiv preprint, we illustrate the use of this technique on groups of wild meerkats carrying GPS collars.
Our paper analysing the role of emotions in open source contributors activity has been accepted for the IEEE International Conference on Social Computing and Its Applications. We focus on a case study based on the bug handling community of the Gentoo Linux project. We show that there are thresholds of emotional expression in textual messages, within the bug tracker and also within related messages in the developers mailing list, that correlate with the likelihood of a contributor to decrease his activity levels. Thus this result stands as step forward towards novel community management tools through quantitative methods.
We proudly announce that our recent work "Betweenness preference: Quantifying correlations in the topological dynamics of temporal networks" has been accepted for publication in the journal Physical Review Letters.
Going beyond the mere aggregate topology or activities of nodes in dynamic networks, in our paper we uncovered a so far unknown temporal-topological dimension of network dynamics. We further show that this new dimension crucially influences dynamical processes like for instance information diffusion or the spreading of diseases.
For a number of complex systems, a simple abstraction of their organization in terms of networks is not sufficient for understanding their structure, dynamics, and function. This observation raises fundamental questions: When are simple network models sufficient and when are they not? What additional ingredients are needed to accurately model the dynamical processes? With access to more and more relational data, what are the most efficient ways to capture the structural information?
These are questions that we would like to address in aour workshop on Higher-Order Models in Network Science, which is co-organized by Dr. Renaud Lambiotte, Dr. Martin Rosvall and Dr. Ingo Scholtes. The satellite will be co-located with NetSci 2014, the premiere international conference on complex networks. It be held on Tuesday, June 3rd, 2014 at University of California, Berkeley.
Today, Dr. Ingo Scholtes will give a talk on our recent work Categorizing Bugs with Social Networks at SE2014, the most important software engineering conference held in the german-speaking countries. Contributions to SE 2014 were on an invitation-only basis and required a previous publication at one of the international top-notch software engineering conferences. We are proud that the organizers identified our work as one of the last years' top contributions to the field of software engineering.
In our work, we quantitatively studied the importance of social structures on distributed software engineering processes. In particular, we combine Big Data techniques, network analysis and predictive analytics to automatically assess bug report quality. Our method can be used to improve the bug handling processes of large-scale Open Source Software communities. This work is an outcome of our research line of social software engineering and has been funded by the SNF in the context of a research project on distributed software engineering.
The second international workshop on "Self-optimisation in Organic and Autonomic Computing Systems", which is co-organized by Dr. Ingo Scholtes, will be held tomorrow, February 25th 2014, in Lübeck, Germany.
The workshop will address the engineering of complex, self-optimising systems. Co-located with the long-tradition International Conference on Architecture of Computing Systems (ARCS), the workshop will be targeted at computer scientists and engineers, who want to better understand how self-optimising systems can be designed. A special discussion session, moderated by Dr. Ingo Scholtes, will address research challenges arising in the engineering of complex multi-layer systems.
A talk by Dr Nicolas Perony on animal social complexity has been picked by the TED team and is now part of the TED video library. Nicolas, postdoc in our group, talks about his research on the social structure of groups of wild bats and meerkats.